Conventionally, there are robots known to perform a so-called pick operation that is an action of holding and moving a workpiece such as a bolt and an electronic component placed in a component box by a robot hand provided at a movable end part of an arm thereof.
Such a robot performs a holding action by pinching a workpiece with a plurality of holding claws provided at an end portion of a robot hand (for example, see Japanese Patent Application Laid-open No. 2002-283268). The holding claws are secured to respective moving parts separately provided on the robot hand, and the above-mentioned pinching is performed by moving each of the moving parts in a direction to come close to one another.
However, in conventional robot hands and robots, there may be a situation where it is difficult to hold a workpiece depending on the size or the shape of the workpiece that is a subject to hold because the size and shape of the holding claws are fixed.
In this regard, the technology disclosed in the above-mentioned Japanese Patent Application Laid-open No. 2002-283268 recites that a variety of workpieces can be accommodated by adjusting a moving amount of the moving parts. However, when the shape of the holding claws does not fit to a workpiece in the first place, it is sill difficult to hold the workpiece.